The present and continuing increase in data traffic volumes and the requirement for speed of switching and reduced energy consumption in datacenters has driven a great deal of recent innovation. In particular, it has been realised that optical switching offers many of the desired properties but optical devices need to be controlled by and interfaced with electronic devices including traditional electronic data servers. Optical devices themselves do not necessarily reduce the size or complexity of a switch. However, in datacenter switch architectures the array waveguide grating has a central role since it is a passive and robust device achieving routing based upon input carrier wavelength.
As an example of earlier work in the area of AWG based optical switches, U.S. Pat. No. 8,792,787 provides a hybrid optoelectronic packet switch which has several stages and layers of AWGs. This invention includes a buffering stage in the electronic domain in order to avoid blocking and there is a master scheduler which is responsible for routing an input signal across the switch fabric to the output port. The switch of U.S. Pat. No. 8,792,787 is a large device and is not scalable.
From GB1403191.8 (U.S. Ser. No. 14/629,922) detector remodulators (DRMs) are known for receiving an optical signal, regenerating and retransmitting it, either on the same or different carrier optical wavelength. From GB1420063.8 it is known that a packet switch can be built from DRMs and AWGs, the DRMs configured to route packet signals in response to a central scheduler.
There remains a desire to reduce the component count in an optoelectronic switch and to simplify the connectivity within the switch. Thus an aim of the present invention is to provide improved switch functionality whilst reducing the component count.